This invention concerns electrolysis of water-borne slurries, suspensions and solutions for treatment of the water, either for purification or other purposes. More specifically, the invention is directed to a specific configuration of electrolytic device through which liquid can flow on a continuous basis for treatment by electrolysis.
The effects of electrolysis on water and water-borne substances are well known. This includes processes for the complete breakdown of water into elemental hydrogen and oxygen gas, as well as other electrolytic processes such as to divide water into alkaline and acidic components, to produce halogen gases, and to purify water. See, as examples, the following U.S. Pat. Nos.: 2,546,254 (Briggs); 3,984,303 (Peters); 4,014,777 (Brown); 4,113,601 (Spirig); 4,121,991 (Miller): 4,169,035 (Stummer); 4,426,261 (Fushihara); 4,612,104 (Holmes); 4,676,882 (Okazaki). The use of electrolysis in purification of water and aqueous solutions and suspensions involves the precipitation of impurities, possibly due in part to production of atomic oxygen in the electrolytic process, the atomic oxygen existing only for a very short time before combining with impurities.
The Peters patent referenced above, disclosing a tubular electrolytic device through which aqueous solutions flow generally axially, is concerned with the production of halogen gas and alkali metal hydroxides. The patent describes a hollow tubular cathode member with a hollow tubular anode member positioned concentrically within the cathode. The two electrodes have liquid permeable walls. An outer shell surrounds the cathode member, rather than the cathode itself providing the liquid-containing housing.
The Spirig patent shows a water decomposing electrolytic device which involves cone-shaped compartment structures arranged concentrically, but those shapes are dictated by construction considerations rather than by flow considerations. The flow of liquid in the Spirig patent is very different from that of the present invention. The Miller patent describes an electrolytic cell for water purification, the water flowing axially through the cylindrical device but not in the manner or with the flow structure of the present invention. In the different embodiments described by Miller, at least one of the electrodes is provided by blade-like radially arranged components within the cylindrical shell.
The Stummer patent shows an axial-flow electrolytic cell for treatment of aqueous solutions wherein the liquid flows between generally concentric electrodes. Concentric cones are shown in an embodiment disclosed by Stummer, but not concentric cone-shaped electrodes both of which confine the flowing liquid during electrolytic treatment. The patent is primarily concerned with avoiding the formation of deposits on the electrodes, particularly the cathode.
Fushihara shows another concentric cylindrical arrangement in an electrolytic device. Holmes describes an electrolytic cell which includes concentric inner and outer electrodes and in which the inner electrode has some conical portions. The aqueous solution flows axially between the electrodes, but inflow and outflow are not axial but radial. The patent is concerned with variation in flow cross section, for controlling the deposition of salts into preferred areas.
The Okazaki patent shows another concentric-cylinder electrolytic device, in which influent and outflow are not axial.
It is among the objects of this invention to improve continuous-flow electrolytic cells used in treatment of aqueous solutions, in efficiency of construction and electrolytic operation.